It is known that certain N-(5-amino-2-cyano-4-fluoro-phenyl)-alkanesulphonamides, such as, for example, N-(5-amino-2-cyano-4-fluoro-phenyl)-methanesulphonamide, are obtained when corresponding halogenated benzene derivatives, such as, for example, 1-amino-4-cyano-2,5-difluoro-benzene, are heated with alkanesulphonamides, such as, for example, methanesulphonamide, in the presence of an acid binder, such as, for example, potassium carbonate, and in the presence of a diluent, such as, for example, N-methyl-pyrrolidone (see EP-A-648772). However, this process affords the desired products in unsatisfactory yields. Accordingly, there is a need for a more favourable preparation process for N-(5-amino-2-cyano-4-fluoro-phenyl)-sulphonamides.